1. Field of the Invention
This invention relates to a treatment apparatus for cleaning or drying semiconductor wafers, LCD glass substrates, or other objects to be treated, for example.
2. Description of the Prior Art
In the field of semiconductors, in general, there are widely employed various treatment apparatuses, such as cleaning apparatuses for cleaning semiconductor wafers, LCD glass substrates, or other objects to be processed (hereinafter called wafers, etc.) by sequentially immersing them in a cleaning vessel or other treatment portion storing a chemical liquid, such as ammonia water (NH.sub.4 OH) or hydrofluoric acid (HF), cleaning liquid, such as rinsing liquid (pure water), and drying apparatuses for drying wafers, etc. which have been cleaned.
A widely used conventional cleaning apparatus of this type includes a cleaning vessel or other treatment means which store a cleaning liquid to immerse wafers, etc. into the cleaning agent to clean their surfaces; a cleaning liquid supply pipe connecting the cleaning vessel to a pure water supply source; and a chemical liquid reservoir storing a chemical liquid and connected to the cleaning liquid supply pipe, so as to infuse the chemical liquid to the pure water flowing through the cleaning liquid supply pipe with the aid of a compressed carrier gas, such as nitrogen (N.sub.2) gas, into the chemical liquid in the chemical liquid reservoir so that the chemical liquid of a predetermined concentration be supplied into the cleaning vessel and used for cleaning objects to be processed.
A widely used conventional drying apparatus includes a drying chamber or other treatment portion for applying a drying gas onto wafers, etc. to dry them; a N.sub.2 gas supply pipe connecting the drying chamber to a supply source of a drying gas carrier gas, such as N.sub.2 gas,; a chemical liquid container storing a chemical liquid such as IPA (isopropyl alcohol) or other organic solvent; and a drying gas generator interposed in the N2 gas supply pipe, so as to compress IPA in the chemical liquid container with the N.sub.2 gas or other carrier gas and to infuse it to the drying gas generator, such that the drying gas of a predetermined concentration be supplied into the drying chamber and used to dry objects to be processed.
However, since these conventional treatment apparatuses were configured to compress a chemical liquid stored in the chemical liquid container by using a pressurized inert gas such as N.sub.2 gas, and to inject the chemical liquid into a pure water line or the dryer gas generator, the supplied amount of the chemical liquid was liable to vary with changes in flow rate of pure water or dryer gas or with changes in pressure. It inevitably caused fluctuation in concentration of the chemical liquid in the pure water or in the drying gas, a decrease in cleaning efficiency or drying efficiency, and a decrease in manufacturing yield.